U.S. patent number 5,832,948 [Application Number 08/777,681] was granted by the patent office on 1998-11-10 for liquid transfer system.
This patent grant is currently assigned to Chemand Corp.. Invention is credited to Daniel Schell.
United States Patent |
5,832,948 |
Schell |
November 10, 1998 |
Liquid transfer system
Abstract
The liquid transfer system includes a liquid supply tank and at
least two pressurizable liquid holding vessels. The liquid holding
vessels are placed beneath the supply tank, and a liquid supply
line connects the supply tank to each vessel. The liquid supply
line is operated as a siphon from the tank to each vessel, in order
to move liquid from the tank to each vessel. Each vessel is
alternately filled and pressurized to dispense liquid from the
vessel, such that one vessel is being filled while the other is
dispensing liquid, and a constant controllable liquid output flow
is achieved. A preferred embodiment includes a liquid recycling
line to recycle or constantly move the liquid within the system to
achieve thorough mixing, and an in-line filter to improve liquid
purity.
Inventors: |
Schell; Daniel (San Jose,
CA) |
Assignee: |
Chemand Corp. (San Jose,
CA)
|
Family
ID: |
25110947 |
Appl.
No.: |
08/777,681 |
Filed: |
December 20, 1996 |
Current U.S.
Class: |
137/93; 137/126;
137/208; 137/263; 137/256; 137/145; 137/142 |
Current CPC
Class: |
B67D
7/007 (20130101); B67D 7/78 (20130101); G01F
3/36 (20130101); G01F 11/28 (20130101); F04F
10/00 (20130101); B67D 7/0272 (20130101); Y10T
137/0396 (20150401); Y10T 137/3124 (20150401); Y10T
137/2863 (20150401); Y10T 137/469 (20150401); Y10T
137/2509 (20150401); Y10T 137/2842 (20150401); Y10T
137/2733 (20150401); Y10T 137/4807 (20150401) |
Current International
Class: |
B67D
5/01 (20060101); B67D 5/60 (20060101); B67D
5/02 (20060101); F04F 10/00 (20060101); G01F
11/28 (20060101); G01F 3/00 (20060101); G01F
11/00 (20060101); G01F 3/36 (20060101); G05D
007/06 () |
Field of
Search: |
;137/5,93,126,142,145,208,256,263 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Michalsky; Gerald A.
Attorney, Agent or Firm: Guillot; Robert O.
Claims
What I claim is:
1. A liquid transfer system comprising:
a liquid supply tank;
at least two pressurizable liquid holding vessels;
a liquid supply line being connected between said tank and each
said vessel for supplying liquid from said tank to each said
vessel; said liquid supply line being engaged to said tank to act
as a liquid siphon in withdrawing said liquid from said tank and
supplying said liquid to said vessel;
a siphoned liquid sensor means being operatively engaged within
said liquid supply system to provide an indication that siphoned
liquid is passing from said liquid supply tank to said liquid
holding vessels; and
a liquid output line being operatively engaged to said liquid
holding vessels for the transfer of liquid therefrom.
2. A liquid transfer system as described in claim 1 wherein said
vessels are disposed beneath said tank, such that a liquid level
within said vessels is at all times lower than a liquid level
within said tank; and
wherein said siphoned liquid sensor means is operatively engaged
within said liquid supply system to detect the presence of siphoned
liquid within said liquid supply line.
3. A liquid transfer system as described in claim 1 wherein a
vacuum from at least one of said vessels is utilized to initiate
said siphon.
4. A liquid transfer system as described in claim 3 wherein a gas
line is engaged to said vessel to create said vacuum in said
vessel.
5. A liquid transfer system as described in claim 3 wherein said
vacuum is applied to said liquid supply line.
6. A liquid transfer system as described in claim 1 wherein said
tank is pressurizable and a gas supply line is engaged to said tank
to supply pressurized gas to said tank to initiate said siphon.
7. A liquid transfer system as described in claim 1 wherein a gas
supply line is engaged with said tank to supply volumetric
replacement gas for liquid withdrawn from said tank.
8. A liquid transfer system as described in claim 1 wherein a
vessel gas line is engaged to each said vessel to remove gas from
said vessel as liquid is inlet into said vessel.
9. A liquid transfer system as described in claim 8 wherein
pressurized gas is suppliable through said vessel gas line to each
said vessel to transfer liquid out of said vessel.
10. A liquid transfer system as described in claim 9, further
including a first liquid flow control valve being disposed in said
liquid supply line for the selectable dispensing of said liquid
from said liquid supply tank to each said vessel.
11. A liquid transfer system as described in claim 10, further
including a second liquid flow control valve being disposed to
receive liquid from each said vessel and to output said liquid to a
liquid output line.
12. A liquid transfer system as described in claim 11, further
including a liquid return line for supplying liquid from said
vessels to said tank, and including a third liquid flow control
valve being disposed within said liquid output line for selectably
supplying liquid from said vessels to said liquid return line.
13. A liquid transfer system as described in claim 12, further
including a liquid filtration system being engaged in said liquid
output line for filtering liquid passing therethrough.
14. A liquid transfer system as described in claim 11 wherein a
programmable electronic control unit is utilized to control the
opening of said first and second liquid control valves to operate
said system.
15. A liquid transfer system as described in claim 9 wherein a gas
pressure control valve is disposed in said vessel gas supply line
to selectably control the gas pressure supplied to said vessels,
and thereby control the liquid flow rate from said vessels.
16. A liquid transfer system as described in claim 15 wherein a
programmable electronic control unit is utilized to control the
opening of said gas pressure control valve.
17. A liquid transfer system as described in claim 1 wherein a
deionized water supply line is engaged to said liquid supply line
to provide deionized water into said liquid supply line for
intermixing thereof with said liquid in said liquid supply
line.
18. A liquid transfer system as described in claim 17 further
including a liquid concentration detection means to provide liquid
concentration data of liquid contained within said system for
controlling the quantity of deionized water that is intermixed with
liquid in said system.
19. A liquid transfer system as described in claim 1, further
including a liquid sample port being engaged with said liquid
output line for receiving liquid therefrom for the analysis
thereof.
20. A liquid transfer system as described in claim 19, wherein a
source of deionized water is provided to said liquid sample port to
clean said sample port.
21. A liquid transfer system as described in claim 1, further
including at least one other liquid holding tank being engaged with
a second liquid supply line for supplying further liquid to said
liquid holding vessels.
22. A liquid transfer system as described in claim 1 wherein said
tank is disposed within a pressurizable cabinet.
23. A liquid transfer system comprising:
a liquid supply tank;
at least two pressurizable liquid holding vessels;
a liquid supply line being connected between said tank and each
said vessel for supplying liquid from said tank to each said
vessel, said liquid supply line being engaged to said tank to act
as a liquid siphon in withdrawing said liquid from said tank and
supplying said liquid to said vessels;
a vacuum means being operatively engaged to said liquid supply line
to initiate said liquid siphon within said liquid supply line;
a siphoned liquid sensor means being operatively engaged within
said liquid supply system to provide an indication that siphoned
liquid is passing from said liquid supply tank to said liquid
holding vessels; and
a programmable electronic control unit being engaged to said
siphoned liquid sensor means and to said vacuum means and operating
to turn off said vacuum means when said passing of siphoned liquid
is indicated.
24. A liquid transfer system as described in claim 23 wherein a
vacuum from at least one of said vessels is utilized to initiate
said siphon.
25. A liquid transfer system as described in claim 24 wherein a
vessel gas line is engaged to each said vessel to remove gas from
said vessel as liquid is inlet into said vessel.
26. A liquid transfer system as described in claim 25 wherein
pressurized gas is suppliable through said vessel gas line to each
said vessel to transfer liquid out of said vessel.
27. A liquid transfer system as described in claim 23 further
including a liquid filtration system being engaged in said liquid
output line for filtering liquid passing therethrough.
28. A liquid transfer system comprising:
a liquid supply means;
at least two pressurizable liquid holding vessels;
a liquid supply line being connected between said liquid supply
means and each said vessel for supplying liquid from said liquid
supply means to each said vessel, said liquid supply line being
engaged to said liquid supply means to act as a liquid siphon in
withdrawing said liquid from said tank and supplying said liquid to
said vessels;
a gas pressure means being operatively engaged to said liquid
supply means to initiate said liquid siphon within said liquid
supply line;
a liquid output line being operatively engaged to said liquid
holding vessels for the transfer of liquid therefrom.
29. A liquid transfer system as described in claim 28, further
including:
a siphoned liquid sensor means being operatively engaged within
said liquid supply system to provide an indication that siphoned
liquid is passing from said liquid supply tank to said liquid
holding vessels; and
a programmable electronic control unit being engaged to said
siphoned liquid sensor means and to said gas pressure means and
operating to turn off said gas pressure means when said passing of
siphoned liquid is indicated.
30. A liquid transfer system as described in claim 28 wherein said
liquid supply means comprises a liquid supply tank, and said liquid
supply tank is pressurizable and said gas pressure means is
operatively engaged to said liquid supply tank to provide
pressurized gas to said liquid supply tank.
31. A liquid transfer system as described in claim 28 wherein said
liquid supply means comprises a non-pressurizable liquid supply
tank that is disposed within a pressurizable enclosure.
32. A liquid transfer system as described in claim 28 wherein said
liquid supply means includes a liquid supply tank having an ambient
pressure opening therethrough, and wherein said tank is disposed
within a pressurizable enclosure;
and wherein a gas pressure means is operatively engaged to said
pressurizable enclosure to supply pressurized gas into said
enclosure to initiate said siphon;
and further including a siphoned liquid sensor means to detect the
presence of siphoned liquid within said liquid supply line;
a programmable electronic control unit being engaged to said
siphoned liquid sensor means and to said gas pressure means and
operating to turn off said gas pressure means when siphoned liquid
is detected within said liquid supply line.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to systems for transferring
liquid from a storage tank to an output line, and more particularly
to liquid transfer systems utilized in the semiconductor industry
wherein high purity and accurate liquid flow rate controls are
necessary.
2. Description of the Prior Art
Many semiconductor manufacturing steps require the utilization of
high purity liquids, such as acids and solvents, and various liquid
transfer systems are utilized to deliver such liquids. Because the
manufacturing steps must be precisely controlled, similar precise
controls are required in the delivery of the liquids, such as
precise liquid flow rates with minimal variance in the flow rates.
Therefore, liquid delivery systems which rely upon pumps to move
the liquid are less desirable than systems which move liquid
without utilizing pumps.
Prior art liquid delivery systems that do not use pumps, generally
utilize controlled gas pressure within a pressurizable liquid
holding vessel to push liquid from the vessel in a controllable
manner. Systems utilizing two pressurizable liquid holding vessels
to alternatively deliver liquid are known in the prior art, wherein
one vessel is filled while the second vessel is pressurized to
dispense liquid therefrom. By alternately filling and dispensing
liquid from two pressurizable vessels, a constant, controllable
flow of liquid is obtained. However, the inputting of liquid into
the vessels during the fill cycle can be problematical. The prior
art utilizes a constant vacuum, pumping, or significant pressure to
move liquid from a supply tank to each vessel during the fill
cycle. The constant vacuum or pressure can alter the delicate
chemistry of some types of liquids, such as by removing volatile
organic compounds from solvents or adding small bubbles into the
liquids, where such bubbles are detected and identified as
particulate impurities in the liquid. Pumping such high purity
chemistries can contaminate with both particles and trace metal
ionics.
The present invention provides an improvement on such liquid
transfer systems by placing the pressurizable vessels beneath the
supply tank, such that a siphon effect can be utilized to transfer
liquid from the supply tank to the vessels. Once a siphon effect
has been established, there is no further need for pressure or
continued vacuum effect to move the liquid from the supply tank to
the vessels, thus improving the quality of the output liquid from
the system.
SUMMARY OF THE INVENTION
It is an advantage of the present invention that neither
significant pressure nor significant vacuum is necessary to
transfer liquid from a supply tank to a liquid holding vessel.
It is another advantage of the present invention that it utilizes a
siphon effect to transfer liquid from a supply tank to a liquid
holding vessel.
It is a further advantage of the present invention that high purity
liquids are dispensed for semiconductor manufacturing process
steps.
It is yet another advantage of the present invention that the
occurrence of small bubbles in dispensed liquids is reduced.
It is yet a further advantage of the present invention that an
automated liquid transfer system is provided which delivers high
purity liquids at controlled flow rates.
The liquid transfer system of the present invention includes a
liquid supply tank and at least two pressurizable liquid holding
vessels. The liquid holding vessels are placed beneath the supply
tank, and a liquid supply line connects the supply tank to each
vessel. The liquid supply line is operated as a siphon from the
tank to each vessel, in order to move liquid from the tank to each
vessel. Each vessel is alternately filled and pressurized to
dispense liquid from the vessel, such that one vessel is being
filled while the other is dispensing liquid, and a constant
controllable liquid output flow is achieved. A preferred embodiment
includes a liquid recycling line to recycle or constantly move the
liquid within the system to achieve thorough mixing, and an in-line
filter to improve liquid purity.
These and other features and advantages of the present invention
will become apparent to those skilled in the art upon review of the
following detailed description.
IN THE DRAWING
FIG. 1 is a schematic diagram depicting the basic liquid transfer
system of the present invention;
FIG. 2 is a cross-sectional depiction of a 3-way valve utilized in
the present invention;
FIG. 3 is a cross-sectional view of a 3-way valve utilized in the
present invention;
FIG. 4 is a cross-sectional view of a 2-way valve utilized in the
present invention;
FIG. 5 depicts an expanded liquid transfer system of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a detailed depiction of a preferred liquid transfer
system 10 of the present invention, wherein gas pipes are shown as
a single line and liquid pipes are shown as a double line. As
depicted in FIG. 1, a liquid supply tank 14 is disposed in a
vertically elevated position relative to two pressurizable liquid
holding vessels 34 and 42. In the preferred embodiment, the tank 14
is a 55 gallon drum, as is commonly found in the chemical industry;
however, other types of tanks, such as canisters and totes of any
size are contemplated in this invention. A lid 16 is disposed upon
the tank 14. In some system installations the lid 16 may be open to
atmospheric pressure, while in other system installations the lid
16 is engaged to the tank with a pressurizable seal, such that the
stability of the chemistry of the liquid in the tank 14 is
maximized and the tank 14 is pressurizable, as will be discussed
hereinafter. A liquid supply line 20 is engaged to the tank 14
through the lid 16, such that an internal tank line portion 22 of
the liquid supply line 20 projects downwardly to a line end 24
disposed at the bottom of the tank 14. The liquid supply line 20
delivers liquid to the two vessels 34 and 42, which are disposed
beneath the tank 14, such that the internal tank line 22 with end
24 comprises a siphon line 26, and a siphon effect is utilized to
transfer liquid from tank 14 to the vessels 34 and 42.
The utilization of the siphon line 26 is significant in that it
permits the simple placement and installation of 55 gallon drums in
a vertical orientation and allows for the efficient removal of
liquid therefrom. Because many chemical processes have stringent
chemical purity requirements, it is advantageous to be able to
remove liquid from the tank 14 without the use of significant
vacuum means. Specifically, it is known that the use of significant
vacuum to transfer liquids can alter the normality of the
chemistry, resulting in degraded performance of the chemistry. The
use of a siphon line 26 through supply line 20 thus takes advantage
of gravitational forces and produces improved chemical properties
in the liquid transfer system 10. A detailed description of further
features of the liquid transfer system 10 is next provided.
The liquid supply line 20 is connected from the liquid supply tank
14 to a 3-way valve 30 (also identified with the letter A) which is
described hereinafter in detail with the aid of FIG. 2. A line
sensor 28 in line 20 is used to indicate the presence or absence of
liquid in line 20. The valve 30 may be activated to supply liquid
to a first pressurizable liquid holding vessel 34 through line 38
or to a second pressurizable liquid holding vessel 42 through line
46. Liquid from vessel 34 is deliverable to a 3-way valve 50 (also
identified with the letter B and depicted in FIG. 3 herebelow)
through line 54, whereas liquid from tank 42 is deliverable to the
3-way valve 50 through line 58. Liquid from the valve 50 is
delivered to liquid flow line 62 to a 2-way valve 66 (also
identified with the letter F and depicted in FIG. 4). Liquid
normally flows through the valve 66 to the liquid feed line 70 and
then to filters 74, but if valve 66 is activated the liquid flows
to a drain line 80. In this preferred embodiment, two filters 74
are placed in parallel in line 70 to remove unwanted impurities
from the liquid. A liquid return line 84 that is accessible
utilizing valves 88, can be utilized to recirculate liquid from the
filters back to the supply tank 14. Normally, liquid passing
through filters 74 is piped through parallel lines 92 to the liquid
outlet flow control valve 96 and sensor 100, to the output line
104. In some system installations a liquid inlet return line 106
may be utilized to return liquid to tank 14 that has been output
through line 104 to a user process.
The flow of liquid from the vessels 34 and 42 is controlled by gas
pressure, preferably utilizing a relatively inert gas such as
nitrogen, although air or other gasses may be used in various
applications. As depicted in FIG. 1, nitrogen from a source 120 is
fed through delivery line 124 to a 3-way valve 128 (also identified
with the letter E). In a first gating from valve 128, pressurized
gas is fed through a line 132 that is controlled by a gas regulator
136 to a 3-way valve 140 (also identified with the letter D).
Pressurized gas can then be gated from valve 140 to vessel 34
through gas line 144 or to vessel 42 through gas line 148.
Returning to valve 128, the left hand gating from valve 128
delivers pressurized gas through a gas regulator 150 and line 152
to a gas control valve 156 (also identified with the letter G).
Activation of valve 156 causes pressurized gas to pass through line
160, through regulator 164 to the supply tank 14. The regulator 164
permits gas to enter the tank 14 to provide volumetric gas
replacement for liquid removed from tank 14 or to enhance/assist
the siphon effect.
In order to fill tanks 34 or 42 with liquid, it is necessary to
outlet any gas present in vessels 34 and 42 that is displaced by
inletted liquid. To accomplish the outletting of gas from vessels
34 and 42, a 3-way valve 180 is engaged by gas lines 184 and 188 to
lines 144 and 148 respectively. The 3-way valve 180 is preferably
connected to the suction orifice 192 of a venturi valve 196 which
is connected to a gas exhaust 200. Pressurized gas to operate the
venturi valve 196 is delivered through gas line 204 which is
connected through a gas regulator 208 to pressurized gas line 152
that is connected to valve 128. Therefore, when valve 180 is opened
it permits the outletting of gas from vessels 34 or 42 during the
liquid filling of those tanks. Additionally, if the venturi valve
196 is activated, a suction force can be applied through valve 180
to facilitate the removal of displaced gas from vessels 34 and 42.
A drain line gas exhaust line 220 is connected between the drain
line 80 and the exhaust 200.
It is therefore to be generally understood that when liquid is
present in supply tank 14 and valve 30 is opened to either vessel
34 or 42 that a siphon effect (assuming that liquid is present in
line 20) will cause the liquid to flow from supply tank 14 into a
vessel 34 or 42, with replacement gas flowing into tank 14 through
valves 128 and 156.
The primary means for initiating a siphon from tank 14 is through a
vacuum from the siphon line 26. To initiate the vacuum, gas valve
128 is opened and valve 156 is closed to cause pressurized gas to
flow through line 204 to the venturi 196. This causes a vacuum to
be created from the suction orifice 192 of the venturi valve 196
back to the valve 180. Valve 180 may be opened to either vessel 34
or 42 through line 184 or 188, and when valve 30 is opened to the
appropriate line 28 or 46 from tanks 34 or 42 respectively, the
vacuum will be created in line 20 back to tank 14. Once a siphon
flow is initiated the vacuum effect is discontinued as the gravity
induced flow of the siphon will continue to cause fluid movement
from tank 14 when required in the system. It is important with
volatile liquids to remove the vacuum pressure that initiates the
siphon as soon as is possible to preserve VOCs in the liquid and
not affect the chemistry of the liquid. Additionally excess vacuum
exposure can add bubbles into the liquid, resulting in difficulty
in qualifying the chemistry for ultra high purity applications.
Additionally, as a second means for initiating a siphon through
pipe 20, if valves 128 and 156 are appropriately activated,
pressurized gas will be inlet into supply tank 14 to aid in the
flow of liquid from supply tank 14 through line 20 to vessels 34 or
42, thus filling vessels 34 or 42 with liquid. Such a pressure
assist to the siphon is utilizable both to initiate the siphon and
when a viscous liquid is being processed in the system 10.
An alternating fill-empty process is preferably utilized to
transfer liquid from the vessels 34 and 42 through valve 50 to line
70. To transfer liquid from vessel 34, valves 128 and 140 are
appropriately opened to cause pressurized gas to flow through line
144 into vessel 34, and valve 50 is opened to permit liquid to flow
from vessel 34. When vessel 34 is nearly empty, valve 140 is
activated to cause pressurized gas to flow through line 148, into
vessel 42. Simultaneously, valve 50 is operated to permit liquid to
flow from vessel 42 into line 70. While liquid from vessel 42 is
being emptied through line 70, liquid from supply tank 14 is
simultaneously caused to fill vessel 34, as has been discussed
hereabove. When vessel 42 is nearly empty, valve 140 is activated
to cause pressurized gas to flow through line 144, to cause liquid
to flow from vessel 34, with valve 50 having been appropriately
activated to allow liquid to flow from vessel 34. While liquid
flows from vessel 34, vessel 42 is filled. It is therefore to be
understood that liquid can be constantly transferred through line
70 by alternately filling and emptying vessels 34 and 42. Through
appropriate control of the various valves of system 10, the liquid
flow rate through line 70 can be constantly maintained. It is to be
further appreciated that the liquid delivery system 10 does not use
reciprocating pumps or other devices that cause a pulsating
pressurized liquid flow. Rather, the liquid delivery system 10
provides a constant pressure liquid flow that is very controllable
at low flow rates through control valve 96. For gas control and
safety reasons gas release check valves 230 and 232 are engaged
through gas line 234 to the gas delivery line 160 for tank 14.
To provide a fuller understanding of the operation of the liquid
delivery system 10, a valve table is presented in Table 1 herebelow
wherein "O" means open and "C" means closed and wherein "A" refers
to valve 30, "B" refers to valve 50, "C" refers to valve 180, "D"
refers to valve 140, "E" refers to valve 128, "F" refers to valve
66, and "G" refers to valve 150. The comprehension of the valve
settings as set forth in Table 1 will be well understood by those
skilled in the art in contemplation of FIG. 1, and a detailed
description thereof is therefore unnecessary.
TABLE 1
__________________________________________________________________________
##STR1##
__________________________________________________________________________
.quadrature.DEPENDS ON OTHER PRESSURE VESSEL STATUS cClosed
oOpen
A cross-sectional view of the 3-way valve preferably utilized as
valve 30 is depicted in FIG. 2. This valve is commercially
available from the Marcvalve Corporation, Tewksbury, Mass.,
identified by valve model no. 1003WDTSANPC. The significant
features of the valve are the PTFE valve body 260 with pneumatic
actuators and PTFE Teflon diaphragms 264. The valve 30 is oriented
with an upper inlet orifice 268 and lower outlet orifices 272 and
276. A significant feature of the valve 30 is that no liquid
gathers within the diaphragm chamber due to the lower placement of
the outlet orifices 272 and 276.
FIG. 4 is a cross-sectional view of a preferred 3-way valve 50.
Such a valve is commercially available from the Marcvalve
Corporation, valve model no. 1003WMSBANPC having a PTFE valve body
300 with pneumatic actuators and PTFE Teflon diaphragms 304. The
inlet orifices 308 are disposed in the middle of the valve body
300, whereas the outlet orifice 310 is disposed at the bottom of
the valve body 300, when the valve is properly installed. In this
orientation, the valve 50 is self draining, such that minimal
liquid resides within the valve body 300.
A cross-sectional view of the preferred 2-way valve 66 is depicted
in FIG. 5. Such a valve 66 is commercially available from the
Marcvalve Corporation, valve model no. 1002WTLFANPC, having a PTFE
valve body 320, pneumatic actuators and a PTFE Teflon diaphragm
324. In proper orientation, the valve inlet 326 faces upwardly, the
normal valve outlet 328 is midway disposed and the valve drain
outlet 332 is downwardly disposed at the lower portion of the
diaphragm 324. When the valve 66 is activated, liquid will drain
through outlet 332, such that no liquid will reside within the
chamber of diaphragm 324.
FIG. 5 depicts an expanded liquid transfer system 400, generally
including the liquid transfer system depicted and described
hereabove with regard to FIG. 1; similar structural features are
numbered similarly to those of FIG. 1. System 400 is generally
designed such that its major components are generally contained in
and/or engaged to a single cabinet structure 402, having a
plurality of external interconnections for the input and output of
liquids and gasses, as well as the interconnection of external
components. The tank 14 may be a 55 gallon drum (or a canister or a
tote, etc.) having a lid 16, which may be open to the ambient
atmosphere in situations where purity and chemistry requirements
allow, or may be an air sealed lid where system requirements
dictate. Alternatively, in a preferred embodiment the tank 14 is
disposed within the cabinet structure 402, and the cabinet
structure 402 is sealable and pressurizable while the lid 16 is not
engaged to the tank 14 with a pressurizable seal. In this
configuration the pressurization of the cabinet structure 402 may
be used to create pressure upon the liquid in tank 14; such a
configuration is particularly advantageous when tank 14 is a 55
gallon drum which cannot effectively be pressurized without some
danger of rupture.
The liquid transfer system 400 includes the liquid supply tank 14,
a siphon line 26 which delivers liquid through line 20 to two
pressurizable liquid holding vessels 34 and 42. As with the system
10 of FIG. 1, the vessels 34 and 42 are disposed beneath the tank
14, such that gravitational force and the siphon line 26 are
primarily utilized to transfer liquid from the tank 14 to the
vessels 34 and 42. Nitrogen gas from a source 120 is fed through
valve 140 to alternately pressurize tanks 34 and 42 to transfer
liquid from tanks 34 and 42, as has been discussed hereabove with
regard to system 10. As with system 10, the siphon effect is
preferably started utilizing a vacuum initiated by venturi 196
through vessels 34 and 42 to tank 14.
A first difference between system 400 and system 10 is that the
nitrogen gas line to valve 140 does not pass through valve 128, as
taught in system 10. Rather, in system 400, nitrogen gas from the
source 120 passes through an air operated proportional valve 408.
Valve 408 permits operator control of the gas pressure into tanks
34 and 42 and thus provides control of the liquid flow rate from
vessels 34 and 42. Liquid from vessels 34 and 42 passes through
valve 50 to line 70 that is controlled by an air operated valve
409. Alternatively, liquid from valve 50 can be directed to drain
80 through air operated valve 411. Each of vessels 34 and 42 is
supplied with liquid level detectors 410 which provide control
information regarding the full or empty status of vessels 34 and
42. Additionally, a sensor 404 is utilized to detect liquid flow
from the tank 14. In the preferred embodiment, a capacitive sensor
which senses air in the line is utilized to indicate when the tank
is empty. An alternative method of determining the quantity of
liquid in tank 14 is to place tank 14 upon a scale 406, the output
of which will indicate the fill status of tank 14.
A gas flow meter 412 is disposed in the gas line 152 from valve 128
to tank 14, to control the gas pressure that is input into
pressurizable tank 14. The preferred meter 412 has a range from
0-0.5CFH. A one way check valve 416 is provided in gas line 152 to
further control gas flow throughout the system 400, and a gas line
160 inputs gas from the check valve 416 into tank 14. To provide
gas pressure control, a gas exhaust line 418 that is controlled by
one way check valve 420 is engaged to the gas supply line 160. The
gas exhaust line 416 feeds to the system exhaust 200 in the event
that gas pressure greater than that allowed by check valve 420 is
experienced in the system gas lines. Additionally, the preferred
embodiment includes a nitrogen gas spray nozzle 422 that is
controlled by air operated valve 424 engaged in line 426 from gas
supply line 124.
System 400 includes a sample port 430 and a sump 440 as additional
features, not included in the basic system 10 of FIG. 1. Sample
port 430 is utilized to provide the operator with selectable
samples of the liquid that is flowing through the system 400. To
achieve this, a sample line 434 is engaged to an output line 84
from the filters 74. An air operated valve 436 is utilized to
control the flow of liquid through the sample line 434 to the
sample port 430. A sample port drain line 438 is utilized to drain
liquid from the sample port 430 to the sump 440. The sump 440
includes a liquid detector 444 and a sump pump 448 which is
utilized to pump any liquid resident in sump 440 out through sump
line 452, and through a check valve 456 disposed therein, to a
drain line 460 that is connected to the drain line 80. In the
preferred embodiment, the sump pump 448 is air operated through air
line 464 from a source 468 of clean dry air (CDA) that is
controlled by a manual valve 472 and an air operated valve 476. To
facilitate cleaning of the sample port 430, a nitrogen supply line
480, that is operable through air controlled valve 484, is engaged
to the sample port supply line 434, such that nitrogen gas may be
directed to the sample port to clean out and dry out the sample
port 430.
A deionized water supply system 490 is included in the system 400.
The deionized water supply system 490 includes a deionized water
supply line 494, operatable through a manual valve 498 and a gas
operated valve 504, as well as a deionized water return line 508
that is operable through manual valve 512. The return line is
utilized to maintain constant motion of the deionized water through
the supply and return lines when it is not flowing through the
system, in order to prevent stagnation of the deionized water and
the water purity problems that can result from stagnation. As can
be seen in FIG. 5, through the operation of air valve 504,
deionized water can be fed through line 514 to the sample port 430
in order to clean out the sample port 430. A deionized water spray
nozzle 516 may be engaged to supply line 494 through line 518 and
controlled by air operated valve 520.
Deionized water may also be fed through line 524 to an air operated
valve 528 that is disposed in liquid transfer line 20. Thus,
deionized water may be input into line 20 through line 524
utilizing valve 528, in order to clean out vessels 34 and 42, as
well as valves 30 and 50 and generally all of the liquid supply
system lines. Additionally, through valve 528 deionized water can
be controllably added to liquid within the system 400, including
liquid within tank 14, to controllably adjust the concentration of
liquids flowing through the system. To provide liquid concentration
control information, a testing device, such as a conductivity
electrode 534 is installed in the liquid transfer line system, such
as in the liquid return line 84 from the filters 74 to the tank 14.
Thus, utilizing the liquid transfer system 400, deionized water may
be controllably blended with the liquid in tank 14 through
recirculation line 84, until the detector 534 indicates that a
predetermined concentration has been reached, whereupon the blended
liquid can then be output through line 104.
Liquid output through output line 104 is controlled by a manual
valve 540, an air operated valve 544 and a manual valve 548.
Additionally, a pressure transducer 552 is connected to output line
104 to provide control information regarding liquid output pressure
and flow rate. This control information is utilizable to provide
control signals to the proportional valve 408, to control the gas
pressure input to vessels 34 and 42, and thereby control output
liquid flow rates.
In various industrial applications, it will be beneficial to engage
an outside tank 600, which may constitute one or more 55 gallon
drums, a day tank (holding an approximate quantity of liquid that
would be utilized in a day's operation of the system), or other
liquid holding tanks in association with tank 14. The operative
installation of a tank 600 includes a pressure seal lid 602 and a
liquid supply line 604 from tank 600 to an air operated valve 608
engaged in line 20. Liquid from tank 600 can therefore be input
directly through valve 608 into line 20 for further input to
vessels 34 and 42. The end 610 of line 604 is preferably located at
the bottom of tank 600, in a manner similar to end 24 of line 20 of
tank 14. As with tank 14, a line sensor 612 is utilized on the
output line 604 from tank 600 to sense the fill status of liquid
from tank 600, and liquid level sensors 616 are utilized to provide
high and low liquid levels in a tank 600. In the preferred
embodiment, tank 600 is located above vessels 34 and 42, such that
a siphon effect through line 604 can be accomplished. Thus, the
beneficial use of the siphon effect, as described hereinabove with
regard to tank 14, is likewise achievable from the tank 600. A gas
line 620 is engaged to line 152 to provide pressurized gas to tank
600 through its pressure seal lid 602. The gas through line 620 is
utilizable to force liquid through line 604 to initiate the siphon
effect, and to provide volumetric replacement gas when liquid is
siphoned from tank 600.
A liquid return line 630 is provided to return liquid to tank 600.
The liquid return line 630 is operable through a junction 634 in
line 104, through air operated valve 638 in line 642 to air
operated valve 646, which gates liquid either to the tank 14 return
line 84, or to the tank 600 return line 630 which is controlled by
air operated valve 648. A system drain line 650 is connected to the
junction 634 and controlled by air operated valve 652 and check
valve 654 to deliver liquid to drain line 80.
It is anticipated in various industrial installations that external
filters 660 will be utilized in addition to the filters 74. To
accomplish this, a filter feed line 664 is engaged to the liquid
transfer line 70, to a plurality of external filters 660 disposed
in parallel, and thence to a return line 668 which is controlled by
air operated valve 672 to the liquid output line 104. It can
therefore be appreciated that the filters 660 are installed in
parallel with filters 74.
The liquid transfer system 400 described and depicted hereabove is
an automated system which utilizes a plurality of air controlled
valves (such as valve 424) to accomplish liquid transfer
operations. In the preferred embodiment, each of the air controlled
valves is engaged through an air tube 680 to an electronically
controlled solenoid air valve 684 that is generally disposed on a
control panel 688. Each of the solenoid air valves 684 is
electrically controlled by a computerized controller 692.
Electrical signals from the various sensors of system 400, together
with operator instructions to the controller 692 are utilized to
operate the system 400.
While the invention has been shown and described with regard to
certain preferred embodiments, it will be well understood by those
skilled in the art that have read the preceding specification, that
certain alterations and modifications to the system may be made
without departing from the true spirit and scope of the invention.
Therefore, the following claims are to be interpreted as covering
all such alterations and modifications as would fall within the
true spirit and scope of the invention.
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